Theoretical study of optoelectronic performance of hole-transporting material quinoxaline-based with architecture (D-A-D) in perovskite solar cells: A DFT method

• Published in: Journal of molecular liquids 2024-03, Vol.398, p.124296, Article 124296
• Main Authors: Jahanbani, Shabnam, Ghadari, Rahim
• Format: Article
• Language: English
• Subjects: DFT; Hole-transporting materials; Perovskite solar cells; Quinoxaline
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2024.124296

[Display omitted] •New HTMs with end substituents (-OMe, –OH, and –NH2) have energy levels desirable alignment with MAPbI3.•The designed HTMs are usable as HTMs in PSCs with normal architecture (n-i-p).•IFCT method shows that TQ5 has more transmission of net charge (Q = 0.60 e−) and the highest hole contribution (71.38 %).•Considering different results obtained form study, it was found that the TQ5 is best designed HTM.•Hole-electron distribution indices show that TQ5 has better electronic efficiency than other HTMs. Developing ideal small-molecule hole-transporting materials (HTMs) is one of the most effective methods to improve the performance of perovskite solar cells (PSCs). Meanwhile, designing new molecules with theoretical chemistry methods and gaining a more fundamental understanding of the structure-property relationship is significant for developing highly efficient HTMs. In this study, new HTMs were designed based on quinoxaline core. Based on time-dependent density functional theory (TD-DFT) and density functional theory (DFT), the electron transfer mechanism was investigated by hole and electron analysis and inter-fragment charge transfer (IFCT). The results show that HTMs (TQ2, TQ3, TQ5, TQ7, and TQ8) exhibit suitable energy levels. The matched energy levels with MAPbI3 are helpful for the interfacial charge transfer. IFCT and hole-electron distribution indices show that TQ5 has a higher centroid distance (D = 1.74 Å), a greater degree of spatial expansion (H = 4.58 Å), the smaller overlap area (Sr = 0.62), the highest degree separation (t = −0.11 Å), more transmission of net charge (Q = 0.60 e−), and the highest hole contribution (71.38 %). Due to matched energy levels with MAPbI3, superior hole-electron distribution indices, good solubility, and better hole mobility, it is suggested that TQ5 has desirable properties as HTM in perovskite solar cells with (n-i-p) architecture.